Process for the manufacture of soft soap



Patented Apr. 30, 1929.

UNITED STATES PATENT OFFICE.

LOUIS GEORG LEFFER, 0F KAPELLEN, NEAR NEUSS RHINELANID, GERMANY, .AS SIGN OR TO HERMANN BACHSTEIN, OFJSEKLIN, GERMANY.

PROCESS FOR THE MANUFACTURE OF SOFT SOAP.

No Drawing. Application filed March 25, 1926, Serial No. 97,449, and in Germany April 4,1925.

The ordinary commercial soft'soaps, in so far as they are potash soaps, are very soft and, even when artificially dried, again at tract moisture from the air, while they are not stable with respect to heat or cold. For giving them a suitable consistency some soda lye or soda is added duringsaponification and a not inconsiderable excess of alkali being provided, whereby however, besides other detrimental attendant phenomena these soaps are rendered unsuitable for many purposes, such for instance as washing silk and wool, and for medicinal and cosmetic purposes. The use of carbonates is mentioned by all authors as being necessary for soft soaps.

The present invention has for its object a process for the manufacture of soft soap 0t any desired consistency, which may be stated to be neutral for all practical purposes and is also stable as regards heat and cold, so that the necessity of en'lploying different processes (recipes) in summer and winter is obviated. Such soft soap can be transported in the form of blocks similarly to margarine.

The invention consists in this, that the oils and fats or their fatty acids, resins are saponitied under pressure without the use of carbonates (potash), it being possible in this process to use oils and fats such as cocoanut oil and palm kernel oil in large quantities, which are not suitable generally for use in large quantities for this purpose. Processes requiring pressure are mentioned in many cases especially for hard soaps, but have been rejected by the industry as useless and unpractical.

In the manufacture of this soap the setting point must be taken in account and it has been found thatin the process according to tho-invention the setting point may be influenced by the addition of hydrocarbons, such as benzene, spindle oil, paraitin oil and the like. The setting point of the soap is the point at which the soap becomes solid. If the setting point of the soap is at 70 degrees C. the soap is stable against temperature changes up to 7 0 degrees C. This addition may be made to the primary material to be saponified or it may be made during the. saponification process and be kept within narrow limits, in general not exceeding 2% of the entire mass the effect is the same. A

further means for influencing the setting point is the addition of cruciferous plant oil for instance rape seed oil, colza oil, black and white mustard oil, jamba oil, or ravison oil. Experiments have shown, that according to the composition of the primary ma- Example.

Cocoanut oil 11 kg. palm kernel oil 12 kg, rape seed oil 10 kg.(or colza oil, or mustard oil or jamba oil or ravison oil) and the requisite quantity of potash lye, the same being composed of caustic potassium (KHO). About 62 kg. caustic potash of 16 B. are treated in an autoclave at a temperature 01 about 130 C. with an internal pressure of 3 atmospheres. The saponification which proceeds uniformly requires about one hour. According to the pressure employed, the time required may be lengthened or shortened.

'An example for the addition of hydrocarbons may be given as follows: cocoanut oil 10.5 kg, palm kernel oil 10.5 kg, soya oil 13.5 kg., white oil (paraffin oil) 1.2 kg. and about 64 kg. potash lye of 13 B.

That I claim is:

1. A process for manufacturing soft soap consisting: of subjecting eocoanut oil, palm kernel oil and rape seed oil together with potash lye in a container to pressure and regulating the setting point by the addition of hydrocarbonsduring the saponification process.

2. A process for making softsoap stable during temperature changes consisting of subjecting oils and their fatty acids and .resins to pressure during sapomfieation and adding to the mass hydrocarbon oils during saponification not to exceed 2" of the entire mass to regulate the setting point thereof.

v3. A process for making soft soap stable during temperature changes consisting of subjecting oils and their fatty acids and resins to pressure during saponilication and regulating the setting point thereof by the addition of -setting producing substance.

In testimony whereof I have signed my name to this specification.

LOUIS GEORG LEFFER. 

